Means for cementing well liners



March 13, 1956 T. s. MABRY MEANS FOR CEMENTING WELL LINERS 5 Sheets-Sheet 1 Filed Feb. 17, 1953 ATTO/@NE V5 March 13, 1956 T. s. MABRY 2,738,011

MEANS FOR CEMENTING WELL LINERS Filed Feb. 17, 1955 s sheets-sheet 2 INVENTOR. 7:5;41/15 /WAQY ATTO ENE ys March 13, 1956 T. s. MABRY 2,738,011

MEANS FOR CEMENTING WELL LINERS Filed Feb. 17, 1953 5 Sheets-Sheet 3 ATTO/e Ns V5 March 13, 1956 T. s. MABRY MEANS FOR CEMENTING WELL LIERS 5 Sheets-Sheet. 4

Filed Feb. 17. 1953 Zoo March 13, 1955- T. s; MABRY MEANS FOR CEMENTING WELL LINERs Filed Feb. 17, 1953 5 Sheets-Sheet 5 JNVENTOR. Fgol Tifo/vm; 5. Meer ffm/@mz w/{walfwn United States Patent O The present inventionrelates to means for cementing liners in oil, gas, water, or other types ofwells. The invention is particularly characterized, in this regard, by the transmissionof rotary motion to the liner during the cementing,` of the same in place in the well bottom.

It has been generally accepted, inthe art, that rotation of the liner while the same is being cemented is beneficial. However," to my knowledge rotary motion has never been heretoforeapplied to the liner, where said liner does not extendtothe surface of the ground. Conventionally, liners are cemented. in place while stationary, or while being reciprocatedl vertically.

The object of the invention, accordingly, ,is to provide a means for rotating the liner in the bottom ofl the hole while circulating cementing slurry therethrough in such a manner as will cause said slurry to encase the liner and rigidly anchor 'the same` in the well bottom, with the slurry or equivalent cementitious material extending, when the operation is. completed, from the lower end of the liner a predetermined distance therealong, toward the surface of the ground.

Other objects will appear from the following descrip tion, the claims appended thereto, and from the annexed drawings, in which like reference characters designate like parts throughout the several views, and wherein Figure l and Figure la are an elevational view of the apparatus in which portions haveY been broken away, Figure l showing the upper, portion thereof and Figure la showing the lower portion and constituting an extension of the lower end of theFigure l showing;

Figure 2 is an enlarged elevational view of a bottom tripping plug; i

Figure 3 is an enlargedl elevational view of a top tripping plug; t

Figure 4 is a longitudinal sectional view taken on line 4-4 of FigureV 3; Y i

Figure 5 is Van enlarged longitudinal. sectional View in which portions have been broken away, of the bottom end of the apparatus, illustrating' the back pressure valve assembly and theplug assembly prior to the circulation of the slurry therethrough;

Figure 6 is a fragmentary longitudinal sectional view showing that part of the apparatus immediately above the part .shown in Figure 5, Figure 61 constituting, in effect, an upward extensioniof the showing' of Figure 5 and illustratingY the seal assembly` and part of the spear and bypass assembly; t

Figure 7` isa transverse sectional view on line 77 of Figure 5, looking down on the back pressure valve assembly;

Figure 8 is a transverse sectional view on line 8 8 of Figure 5, looking down on the. bottom plug of the plug assembly;

Figure 9` is a transverse sectional view on line` 99 of Figure 6, through the lower end portion of `the spear and by-pass` assembly;

Figurey 10! is :al fragmentary longitudinal` sectional view in which portions have vbeen broken away, showing that part of the apparatus immediately above the part shown in Figure 6, the showing of Figure 10 constituting an upward extension of the showing of Figure 6 and showing the upper-portion of the spear and bypass assembly;

Figure ll is a fragmentary longitudinal sectional View in which parts are broken away andl other parts remain in elevation, the illustration` in Figure 11 constituting an upward extension of the part of the apparatus shown in Figure l0, there being shown in Figure l1 a packer assembly and part of theV rotating and setting assembly;

Figure 12 is a transverse sectional view through the spear and bypass assembly, taken on line 12-12 of Figure 10;

Figure 13 is a transverse sectional view taken on line 13-13 of Figure l1;

Figure 14 is a fragmentary longitudinal sectional view Y `showing that part` of the rotating and .setting assembly disposed immediately above the part shown in Figure 1l, the showing of Figure 14 constituting, in effect, an up ward extension of Figure l1.;

Figure 15 is a longitudinal sectional view in which parts remain in elevation, showing the upper end of the rotating and setting assembly and the means for connecting the apparatus to a length of drill pipe or tubing eX- tending above the ground surface, the showing of Figure l5 constituting, in effect, an upward extension of Fig, 14;

Figure 16 is a transverse sectional View through the rotating and setting assembly taken on line 16-16 of Figure 14;

, Figure 17 is a transverse sectional view through the rotating and setting assembly taken on line 174-17 of Figure 14;.

Figure 18. is' a fragmentary view in which partsy are shown in longitudinal section and other parts remain in elevation, showing. the portion of the rotating and setting assembly illustrated in Figure 14, as it appears when shifted from its position of Figure 14 to a clutching position;

Figure 19 is a transverse sectional View on line 19-19 of Figure 18; and

Figure 20 is a view similar to Figure 5, showing the parts as they appear during the operation of forcing cementing slurry through the apparatus constituting the present invention.

The invention comprises a number of main assemblies, disposed one above the other from the bottom. to the top of the apparatus. The lowermost assembly is a back pressure valve assembly 22. Immediately thereabove is a plug assembly 24. Above the plug assembly is a seal assembly 26. A spear and bypass assembly is locatedv above the seal assembly, and above the spear and bypass assembly 28 is a packer assembly 30. At the top endl of the apparatus, a rotating and setting assembly 32 is provided, this being adapted for connection to a length of drill pipe or tubing extending above the ground surface.

Apart from these assemblies, there is a bottom tripping plug and a top tripping plug, which are not parts of any one assembly, but rather, are forcedthrough the several assemblies during' the cementing operation.

Each of the several assemblies, and the tripping plugs, will be described in turn.

Back pressure valve assembly shaped guide shoe 38 havingthe circular, domed' head 4d integral at its periphery with and underlying a tlat, circular base plate 42. The guide shoe 38 is of hollow formation, and welded or otherwise iixedly secured to the outer surface of the head dt), and extending downwardly from said head, is a series of blades 44 having beveled edges. The blades 44 are spaced circumferentially of the head 49, and are disposed equal distances apart, said blades being adapted to dig into the hole bottom in the manner shown in Figure la so as to anchor the guide shoe 38 and cause the same to resist rotation.

Formed in the head 40 is a plurality of apertures 46. These are provided in the event fluid circulation through the guide shoe is necessary to wash out possible obstructions that might be encountered while running the apparatus into the hole.

Centrally disposed in the base plate is a smooth walled opening, and extending downwardly through said opening is a bolt 48. The bolt 4S extends through a center opening formed in a connecting plate 5t), the center openings of plates 42, 56 being registered and the pcripheries of said plates being correspondingly registered. Plate 42 has, spaced about the center opening thereof, apertures 54, these being in registration with apertures 56 of plate 5G. The registered apertures 54, S6 permit circulation of tluid into the guide shoe, for passage of said fluid out of the apertures 46.

Initially, it is desired that the guide shoe and con* necting plate 5t) be held against relative rotation. There fore, shear pins 58 extend as dowels between plates 42 and 50. Later, it will be shown how these pins are sheared to allow plate to rotate while the guide shoe remains stationary and embedded in the hole bottom.

Formed integrally with the plate Sti, and extending upwardly from the marginal portion thereof, is an exteriorly threaded connecting flange 52. This threads upwardly into the interiorly threaded lower end of a cylindrical valve housing or case 60. Valve housing 60 and plate 50 are thus tixedly connected.

Formed in housing 60 are outlet ports 62. These ports are arranged in rows extending longitudinally of the mid-length portion of housing 60, said rows being spaced equal distances apart circumferentially of said housing.

A back pressure valve has been designated generally at 64, and is mounted within the upper end portion of housing 60, above the uppermost of the outlet ports 62. The valve 64 includes a valve body 66 formed cylindrically and having a circumferential tiange 63 threaded to engage complementary, tapered threads 7) formed interiorly of the upper end of housing 60.

Formed in the valve body 66 is a seat 72. Normally seated thereagainst is a conical valve disc 74- iixedly connected to the upper end of a stem '76 sliding in an opening formed centrally in a spider '78 that constitutes part of the valve body 66. Coil spring 8d, interposed between disc 74 and spider 7S, is tensioned to normally retain the disc 74 in a seated position.

ln the upper end of the valve body 66, there is provided a circumferential series of inlet ports 82 (Figures 5 and 7). The upper end of the valve body is further formed with a threaded center opening, in which is tixedly engaged the complementarily threaded lower end of a plug opening rod 84 arranged longitudinally and centrally of the back pressure valve assembly.

A lower liner section 36 has its lower end tapered and threaded complementarily to the threads of the housing 60, said section 86 being threadedly connected to the housing. The lower liner section is one section of the liner to be cemented in place, and is not part of the back pressure valve assembly.

Plug assembly This assembly is best shown in Figures 5, 8, and 20. It has two main parts, a lower plug and an upper plug. The lower plug (see Figure 5) is formed with a cylindrical, axially bored body 88 spaced inwardly from the wall of liner section 86. Vulcanized or otherwise attached to the outer surface of said body is a longitudinal series of rubber plug cups 90. The outer peripheries of said cups are disposed in intimate, wiping contact with the inner surface of the linner section 86.

The axial bore of the plug body 88 has been designated by the reference numeral 92.

Formed integrally upon the upper end of the plug body 88 is an upwardly extended, cylindrical skirt 94. The inner diameter of skirt 94 is substantially greater than the diameter of bore 92, and accordingly, there is dened, at the upper end of bore 92, a shoulder 95. Bearing against shoulder 95 is the lower end of a relatively elongated, cylindrical, axially bored plug mandrel 96. Mandrel 96 is formed, at its lower end, with a circumferential series of longitudinal slots 98, said slots opening at their lower end upon the lower end of the mandrel, and terminating at their upper ends at a location well short of the midlength part of the mandrel.

Shear pins 100 (Figure 8) normally connect the skirt 94, and hence the bottom plug, tixedly to the lower end of the plug mandrel. While the bottom plug and plug mandrel are so connected, a sealing ring 102, seated in a circumferential groove formed in the outer surface of the upper end of skirt 94, prevents leakage between the lower plug and an upper plug. The upper plug has a cylindrical plug body 104, the lower end of which laps the skirt 94 and is sealingly engaged by ring 102. The upper plug body 104 is provided, along its length, with spaced rubber plug cups 166 extending into intimate, wiping contact with the inner surface of liner section 86.

Formed in the inner surface of the upper plug body 104, adjacent the lower end thereof, are inwardly projecting, radially extending lugs 108, said lugs engaging in the upper ends of the slots 98.

At the upper end of the upper plug body 104, l provide an interiorly disposed rubber seal ring that is sealably engaged against the plug mandrel 96. Adjacent the ring 11d there is provided a series of shear pins 112., which normally connect the upper plug body ftxedly to the plug mandrel 9d rlfhe mandrel 96, as Will be seen from Figure 5, projects a substantial distance above the upper plug body 104, within the liner section 86, and is exteriorly formed with tapered threads 1.1.4 that engage in the lower end of a complemcntarily threaded coupler 116.

Seal assembly This assembly is best shown in Figure 6. lt includes a tubular seal mandrel 118 exteriorly threaded and tapered at its lower end for engagement in the upper end of coupler 116. Seal cups 120 are spaced longitudinally of the seal mandrel, and are circumposed thereabout, said seal cups providing seats for rubber seals 122 that extend into engagement with the inner surface of the liner section 86. Spacer sleeves 124 are utilized to space the rubber seals apart selected distances. lt may be noted, in this connection, that considered per se, the seal assembly is not considered new, a seal assembly like that shown at the lower end of Figure 6 being commercially available at present.

At its upper end, the mandrel 118 of the seal assembly is exteriorly threaded, for engagement in the lower end of a coupling element 126, said element serving to connect, to the seal assembly 26, the spear and bypass assembly 28.

Spear and bypass assembly The spear and bypass assembly 28 includes the parts shown at the upper end of Figure 6 and at the lower end of Figure 10. This assembly is also shown to advantage in Figure 9.

The upper end of coupler 126 is threadedly engaged with the complementarily threaded, reduced lower end vsuitable grooves formed in the lower end portion of the Ojack screw, and are spaced longitudinally of the jack screw. One of said rings is disposed at the lower end of the jack screw, to prevent leakage between said screw and the screw housing 130. The remaining rings are disposed at opposite sides of Vbypass ports 138 Vformed in .and spaced circumferentially of the jack screw. The bypass ports 138 are registered with ports 139 formed .in the housing 130. Ports V135 relieve pressure caused by the piston eifect of seals 136 when the bypass ports 13.8 are being closed.

The jack screw is formed, for a substantial part of its length, with left-hand threads 140, and threadedly engaged therewith is the correspondingly threaded inner wall of a slip cone 142. The slip cone 142, adjacent its lower end, is formed with an outer shoulder bearing against the upper end of the screw housing 130, said shoulder defining, between the shoulder and the lower end of the slip cone, a portion of the slip cone that is reduced exteriorly in diameter. The reduced portion of the slip cone -is exteriorly threaded, for engagement in complementary threads formed in the inner wall of the housing 130.

yOver-lying the slip cone, and extending longitudinally thereof, are slip segments 144. The slip segments 144, as best shown in Figure 10, are spaced about the slip cone. The slip cone, in this connection, has a `conicallyv tapered outer surface, the conically tapered outer surface of the slip cone bearing against a correspondingly inclined inner surface on each slip segment. As a result, it 4will be seenl that `the rotation of thekjack screw in one ,directionwill cause the slip cone to shift longitudinally of said jack screw, as a result of which the slip segments willbe adjusted radially ,of the liner section 86. If the slip cone shifts upwardly in Figure 1G, the `slip segments will be forced into engagement with the inner `wall of the `liner section. On the contrary, if the slip cone is shifted Y downwardly in Figure 10, the slip segments will be withdrawn out of engagement with `the liner section.

For the purpose of causing theslipv segments to grip` `the liner section tightly when lforced thereagainst, I provide, on each segment, transversely extended teeth 146, .the teeth 146 being inclined upwardly. Downwardly inclined teeth 148 are also provided on each slip segment, `the teeth 148 being inclined downwardly. 'Teeth 146, 148 cooperate to cause each slip segment to bind tightly Yagainst the adjacent portionof the liner section wall.

`At theirupper ends, the respective. slip segments are integrally connected to a collar 15b. It will be understood, in this regard, that the several slip segments are formed of a material having inherently springable characteristics, thus to permit said segments to be shifted radially ofthe liner. The collar 150 is seated upon a shoulder 152 formed upon the jack screw, above the :threads of the jack screw. l v

To hold the collar 15) in place upon the jack screw, a connecting collar 154 is provided, said collar 154 having an enlarged lower end bearing againstv the collar 150. The collar 154 constitutes a coupling element, being internally threaded for engagement with corresponding ex- `ternal threads provided upon the upper endof the jack nected.at its upper end, to a .coupler 158.

Yso

As will vbecome apparent from the description to be provided hereinafter, the mandrel 156 is appropriately to be considered as part of the rotating and setting assembly, which assembly will be described in detail hereinafter.

Packer assembly The packer assembly, designated generally by the reference numeral 30, is disposedfabove the spear and bypass assembly 28, and is best shown in Figures 1 and la, l1, and 13. This assembly includes an inner barrel 160, said barrel constituting part of the liner to be cemented in place and being threadedly connected, at its lower end, to coupler 158 (Figure 10).

The inner barrel 160, for a substantial part of its length, is exteriorly formed with buttress threads 162. At the lower end of the buttress threads, a circumferential stop collar 164 is xedly secured to and extends about the inner barrel, said collar 164 engaging the lower end of packing or wrapping 166 of canvas or equivalent material. The wrapping 166 is secured in place, about the threads 162, by coils 168, the coils 168 being disposed at opposite ends of said wrapping and being formed from a single piece of wire material. Between the closely coiled end portions of said length of wire material, the wire is laced about the wrapping 166 as at 176.

It will be apparent, from the construction shown in Figure lll, that while ordinarily the wrapping 166 extends longitudinally of the inner barrel for a substantial distance, substantial downward pressure exerted against the upper end of said wrapping will be effective to drive said upper end of the wrapping downwardly, thus to collapse the wrapping and force the wrapping into engagement with the outer casing of the well hole, in a manner to be described in detail hereinafter. The wrapping will thus extend between the liner to be cemented and the outer well casing, thus to form a transverse partition within the hole that will denne the upper limits to which the cementing slurry can be forced during cementing of the inner liner, dened by casing section 86 and barrel 160, in place.

It should be noted at this point, that the packer assembly, considered per se, is not new, and is commercially available;

It should lbe further noted that under some circumstances, the packer assembly might be omitted from the apparatusl It would be omitted, if desired, where the -well bottom has not been provided with a previously set outer casing. Likewise, in some instances it might be advantageous to omit the packer assembly when cementing the liner in an open hole below the lower end of a previously set outer casing, in which instances the liner to be cemented would be lapped inside of the old casing.

The packer assembly, in addition to the inner barrel 160 and canvas wrapping 166, also includes a slip cone 174, hold-down slips 180, a slip ring 190, and an outer barrel 194, all of which will be described in detail hereinafter. Except for a clutch jaw 196 of the inner barrel (which jaw will also be described hereinafter), such an assembly is, per se, not new. The apparatus by which it is ordinarily run into the hole is, however, quite different from mine, as will presently appear.

There is extended into the upper end of wrapping 166 the reduced lower end 172 of slip cone 174. The reduced lower end 172 is interposed between the wrapping and the inner barrel 160.

Formed in the slip cone 174 (Figure 13) are bypass openings 176, said openings registering with similar open* ings formed in the inner barrel. The purpose of said bypass openings will be described in detail hereafter.

At its upper end, the slip cone 174 is exteriorly tapered, and extending outwardly from said tapered surface of the slip cone are shear pins 178, four of which might be used, said shear pins extending into the lower ends of hold-down Slips 180. The hold-down slips 180, as shown from Figure l, are relatively wide, and are spaced Aclosely apart through the provision of longitudinal slots 181 dis' posed therebetween.

The outer surfaces of the several hold-down slips 180 are formed with teeth 182 that will grip the outer casing of the well, when the slips are shifted longitudinally of the slip cone 174 after shearing of pins 178. Several of the pins (say two pins) extend into the wall of the inner barrel 16. The slip cone is internally smooth so that it may slide on the inner barrel. In operation, applica tion of suilicient weight applied to the outer barrel 194 to cause shearing of the several pins 178 extending into the wall of the inner barrel 160 will allow the outer barrel 191iand slip cone 174 to be shifted downwardly and collapse the wrapping 1.66 and also to take out of registration the ports 176. The shear pins 17S attaching the slip segments 1S@ to the slip cone 174 are then sheared through application of sufiicient additional weight thus permitting the slips to be wedged betewen the slip cone and the inside of the casing 240. The slip ring 19t) and the external buttress threads 162 of the inner barrel 166 i.

act to retain the compression that has been applied to the collapsed wrapping and the wedged slips.

Each slip segment 136" is integral with a depending, cylindrical slrirt 186 formed upon a thickened upper portion The upper portion 138 is interiorly recessed to provide a seat for a slip ring 19t), that normally engages against the buttress threads.

The thickened portion 13S is in turn made integral with an externally threaded upper end ilange 1512 of the slip assembly, said end llange 192 being engaged with internal threads formed in the lower end of an outer barrel 194,

The outer barrel 194, as will be noted from Figure l, is of substantial length, said outer barrel having its lower end lapping the upper end of the inner barrel as best shown in Figure i4. The upper end of the inner barrel, in this connection, is slotted lonoitudinally to provide a circumferential series or" upwardly projecting clutch jaws 196.

Rotating and setting assembly Above the clutch jaws 196, the mandrel 156, which is a part or" the rotating and setting assembly, is formed with a circumferential shoulder 198, said shoulder 198 being formed adjacent the lower end of a thickened portion Zilli of said mandrel.

Seated upon shoulders 19S is the lower end of a clutch 282. Referring now to Figure 17, clutch 202 is splined upon the thickened upper end portion 200 of mandrel 156, the portion 2li() having spline ribs 204- extending longitudinally thereof and slidably engaged in inner longitudinal grooves provided upon the clutch 262.

rihe outer surface of the clutch 232 is formed with spaced recesses 266 deiining clutch jaws 207. The clutch jaws .267 are adapted to mesh with the clutch jaws 196 formed upon the upper end of the inner barrel 160, when clutch 262 is shifted longitudinally of the apparatus from the position thereof shown in Figure 14 to the position thereof shown in Figure 18.

A clutch collar or ring 203 bears against the upper end of clutch 262, and exerting a downward pressure against said ring is a spring 216 coiled about the upper end portion 261i of mandrel 156.

At its upper end, the end portion 2li@ (see Figure l5) is externally reduced, tapered, and threaded for engagement in the lower end of an axially bored, elongated guide 212. Spring 216 bears at its upper end against the lower` end of guide 212, guide 212 telescoping in the upper end of the outer barrel 194.

The guide 212, at its upper end, is externally tapered and threaded as at 214, for connection to a coupler 216. Coupler 216 is adapted for connection thereto of one or more lengths of drill pipe or tubing 22) (Figure l). Circurnposed about the coupler 216 is an annular setting dog 218.

lll

Bottom tripping plug In Figure 2, and also in Figure 20, there is shown a bottom tripping plug designated generally by the reference numeral 222. The bottom tripping plug is formed with a relatively elongated, cylindrical, core 224 of solid metal formation. A series of rubber cups 226 is provided upon said core, the cups of said series being spaced longitudinally of and being vulcanized or otherwise fixedly connected to the core. The core 224 has a rounded nose 22S, and adjacent said nose, there is provided an upset 229. The outer diameter of the upset 229 is slightly less than the distance between any pair of the diametrically opposed lugs 108 of the upper plug of the plug assembly 24 (see Figure 20). Thus, the bottom tripping plug can be pumped through the upper plug of the plug assembly without disturbing said upper plug. However, the outer diameter of the upset 229 on the bottom tripping plug is slightly greater than the inner diameter of shoulder 95 of the bottom plug of plug assembly 24. Therefore, the bottom plug, when inserted in the apparatus, is adapted to engage the lower plug of the plug assembly 24, in a manner to be discussed in detail hereinafter.

Upper tripping plug The upper tripping plug has been designated generally at 230, and is shown in Figures 3 and 4. This plug is formed with a solid metal core 232, said core being provided with a longitudinal series of spaced rubber fins or cups 234. An upset 236 is disposed in advance of the forwardmost n 234, said upset merging into a rounded nose 238, the outer diameter of which is slightly greater than the main diameter of the core 232.

Operation At 240, I have designated an outer wall casing, which will have been previously set in the hole. As will be noted from Figure la, the lower end of the outer casing 240 terminates a substantial distance above the bottom of the hole, it being understood that the inner liner defined by easing section 86 and inner barrel 160 are to be cemented in place, with the concrete extending from the bottom of the hole to the packing 166.

Before the apparatus is run into the hole, the slip cone 142 of the spear and bypass assembly 28 (see Figure 10) is adjusted upwardly, by rotation of the jack screw relative to said slip cone, thus to shift the slip segments 144 radially and outwardly into gripping engagement with the liner defined by casing section 86. This will hold, for the time being, the liner against movement longitudinally of the rotating and setting assembly. This will also hold the liner against rotation relative to said rotating and setting assembly. The reason these parts will be held against relative longitudinal or rotative movement is due to the fact that the drill pipe or tubing, extending above the surface of the ground, is connected to guide 212, which in turn is afixed to the upper portion 200 of mandrel 156. Mandrel 156, as shown in Figure l0, is alixed to the jack screw 132. The wedging of slip segments 144 between the jack screw and the liner defined by section 86 holds the parts against movement.

After this step of the operation, the bottom of the drill pipe or tubing on which the equipment is run is screwed into the collar 216 at the upper end of the apparatus. While running the equipment into the well, the drill pipe or tubing is occasionally filled with well fluid. However, fluid may flow from the well bore into the drill pipe or tubing through the packer assembly bypass openings 176 and through the bypass ports 138. In this event, the tiuid would flow from the Well bore inwardly through openings 176, and would move downwardly within the apparatus to bypass ports 138, the fluid then flowing inwardly through the bypass ports 138 into the hollow jack screw 132, said fluid then flowing upwardly into the drill pipe or tubing.

When the entire apparatus has been lowered to the bot- Vtom of' the hole, the drill pipe '.or tubing 220 is rotated in a clockwise direction. This `has the effect of jacking the slip cone 142 from under the 'slip segments 144. The slip segments 144 thus release their grip upon the liner to be cemented. At the same time the rotation of the jack screw is effective to close the bypass 138, since these ports will now be out of registration with the corresponding openings formed in the jack screw. housing 130. The seal rings 136 prevent leakage into the bypass ports.

Fluid circulation is now established by pumping fluid into the drill pipe or tubing 220. The uid is forced downwardly, moving through guide 212, mandrel 156, jack screw 132, seal mandrel 118,-the top and bottom plugs of .plug assembly 24, and into valve 64. Said fluid will exert pressure against the. Valve disc 74, forcing said disc downwardly ofi its `seat 72. The fluid will thus move past valve 64, and through outlet ports 62 into the hole. The uid will travel upwardly Awithin the hole, outside of the apparatus, to the surface. The seal assembly 26, it should be noted, prevents circulation inside the liner.

The drill pipe or .tubing 220 is now lowered, so as to cause clutch jaws 207 to move into mesh withclutch jaws 196 from the position thereof shown in Figure 14. Torque is now applied to the drill pipe or tubing in a clockwise direction, and this will cause the shear pins 58 (Figure to` shear, thus permitting free rotation of the entire apparatus above'the stationary guide shoe. In other words, all parts above the guide shoe will be connected for joint rotation, and will be rotated from above the ground surface, simultaneously with the previouslyv mentioned circulation of drilling or `well lluid therethrough.

The bottom tripping plug is now inserted in the upper end of the apparatus. Said tripping plug is followed immediately by cementing slurry, not shown. The entire apparatus is still being rotated, during this step of the operation. As soon as the desired amount of cementing slurry has been pumped into the drill pipe or tubing, in back of the bottom tripping plug, the top tripping plug 230 is inserted, so as to follow said cementing slurry. Pumping is continued, using drilling mud or some other uid in back of the top tripping plug.

Thus, it is seen that the tripping plugs conne between them, at this stage of the operation, the exact amount of cementing slurry which is to be used. Y

The bottom tripping plug, moving downwardly through the apparatus, will reach, eventually, the bottom plug of plug assembly 24. The upset 229 of the bottom tripping plug will, as previously mentioned, engage, at this time, the shoulder 95 of the bottom plug of said plug assembly.

As a result, a build up in pressure will be noted at the surface, until the shear pins 100 are sheared, sepai I.the top tripping plug, ywhich will be disposed yin Ithe bore of the top plug, vvwill follow it, and the rubber cups '226, engaging against the wall of the bore of the top plug,

` will cooperate with the `top plug in effecting a seal. As

a result, circulation will cease.

The drill pipe or tubing is now lowered until the setting dog 218 contacts .the top .of the outer barrel 194. The weight of the drill 4pipe or tubing is then applied so as to collapse the canvas wrapping 166, shear the pins 178, and wedge the hold-down slips 180.

Collapsing of the wrapping is effective, as previously discussed herein, to provide an abutment within the well above which the cementing slurry cannot rise.

The Vdrill pipe is `now picked up sufficiently for the .guide 212 to be withdrawn from the outer barrel 194 and fluid is pumped into the annular space between the outer casing 240 and .the .tubing or drill pipe. Said uid will wash out any cementing material that may yhave beendisplaced over the top of the outer barrel 194. The uid circulated moves downwardly into the apparatus within the annular space between the outer barrel 194, the inner barrel 1.60, the liner `86, and the mandrel 200, the mandrel 156, the seal assembly 26 and then upwardly through the mandrely 96 and on to the surface through the drill pipe or tubing. The drill pipe or tubing is now pulled from the well, and it .will be seen that the liner will have been mounted in place, while being continuously rotated during the cementing operation.

rating the bottom plug from the plug mandrel and upper plug of plug assembly 24. v

As the bottom plug of the plug assembly is pumped to the valve 64, it will clean the wall of the liner.

When the bottom plug engages against the body of valve 64, and reaches the position shown inFigure 20, the bottom tripping plug 222 will be forced oif the shoulder 95 by the plug opening rod 84. As a result, the cementing slurry will move in the direction of the arrow shown in Figure 20, past the bottom tripping plug, and `past the bottom plug, so as to move through the back pressure valve and out of the outlet port 62. Throughout this stage of the operation, of course, the linerwill be continuously rotated in a clockwise direction.

The top tripping plug 230, following the cementing slurry, will contact the top plug of the plug assembly 24, due to the fact that the upset 236 has a greater diameter than the distance between any pair of diametrically opposite lugs 108. An increase in circulating pressure will now be noted until shear pins 112 are sheared, after which the top plug will be pumped to the bottom, moving out of the slots 100 of the plug mandrel 96.

When the top plug has moved fully into engagement once again with the bottom plug of plug assembly 24,

It will be understood that the liner could be equipped with centralizers to -center it in the hole, and it may also be equipped with rotary type Wall cleaners to scratch and `clean the walls` of the hole, thus permitting the cement or concrete to form an intimate bond with the hole formation face and the outside of the liner. Both centralizers and wall cleaners of this type are at present commercially available.

It is believed apparent that the invention is not necessarily confined to the specific use or uses thereof described above, since it may be utilized for any purpose to which it may be suited. Nor is the invention to be necessarily limited to the specific construction illustrated and described, since such construction is only intended .to be illustrative of the principles of operation and the means presently devised to carry out said principles, it being considered that the invention comprehends any minor change in construction that may be permitted within the scope of the appended claims.

What is claimed is: Y

l. Apparatus for cementing a liner in a well hole comprising: at least one liner section having an outlet at its lower end; check valve means at said lower end of the liner arranged for permitting flow of a cementitious material out of said outlet into a space surrounding the liner within va well hole, while preventing reverse flow of said material into the liner; means at the upper end of the liner for bodily rotating the same; plug means insertible within the liner and acting responsively to pressure exerted from the ground surface to traveldownwardly Within the liner to seal the lower end thereof above said check valve means; and a guide shoe on the lower end of the liner adapted to grip the bottom of the hole, said liner being connected to the shoe for rotation relative thereto.

2. Apparatus for cementing a liner in a well hole comprising: at least one liner section having an outlet at its lower end; a back pressure valve assembly including a normally closed check valve located at said lower end of the liner and arranged to open responsively to pressure exerted at the ground surface against cementitious material inserted within the liner, for permitting ow of said material out of said outlet into a space surrounding the liner within a well hole, while preventing reverse iiow of said material into the liner; means at the upper end of the liner for bodily rotating the same; plug means insertible within the liner and acting responsively to pressure exerted from the ground surface to travel downwardly within the liner into engagement with the back pressure valve assembly to seal the lower end of the liner above said assembly; and a guide shoe on the lower end of the liner adapted to grip the bottom of the hole, said liner being connected to the shoe for rotation relative thereto.

3. Apparatus for cementing a liner in a well hole coniprising: at least one liner section having an outlet at its lower end; a back pressure valve assembly including a normally closed check valve located at said lower end of the liner and arranged to open responsively to pressure exerted at the ground surface against cementitious material inserted within the liner, for permitting flow of said material out of said outlet into a space surrounding the liner within a Well hole, while preventing reverse ilow of said material into the liner; means at the upper end of the l incr for bodily rotating the same; plug means insertible within the liner and acting responsively to pressure exerted from the ground surface to travel downwardly within the liner into engagement with the back pressure valve assembly to seal the lower end of the liner above said assembly; a guide shoe on the lower end of the liner adapted to grip the bottom of the hole, said liner being connected to the shoe for rotation relative thereto; and shearable means normally holding the liner and shoe against relative rotation and proportioned to shear responsive to rotation of the liner following engagement of the shoe with the hole bottom.

4. Apparatus for cementing a liner in a well hole comprising: at least one liner section having an outlet at its lower end; a back pressure valve assembly including a normally closed check valve located at said lower end of the liner and arranged to open responsive to pressure exerted at the ground surface against cementitious matcrial inserted within the liner, for permitting tlow of said material out of said outlet into a space surrounding the liner within a well hole while preventing reverse ilow of said material into the liner; and a rotating and setting assembly at the upper end of the liner for setting the liner in the hole, said assembly including a clutch engageable with the liner to bodily rotate the same following setting of the liner; plug means insertible within the liner and acting responsively to pressure exerted from the ground surface to travel downwardly within the liner into engagement with the back pressure valve assembly so as to seal the lower end of the liner above said check valve; a guide shoe on the lower end of the liner adapted to grip the bottom of the hole, said liner being connected to the shoe for rotation relative thereto; shearable means normally holding the liner and shoe against relative rotation and proportioned to shear responsive to rotation of the liner following engagement of the shoe with the hole bottom; and packing means on the liner wedgable in said space to limit upward movement of said cementitious material.

References Cited in the file of this patent UNITED STATES PATENTS 1,339,955 Hardel May 11, 1920 1,830,851 Murphy Nov. 10, 1931 1,910,442 Manning May 23, 1933 2,111,062 Brown Mar. 16, 1938 2,114,521 Brown Apr. 19, 1938 2,197,920 Brown Apr. 23, 1940 2,392,352 Wright Jan. 8, 1946 

